The subject invention relates to multiplexers and more particularly to apparatus for use in statistical multiplexers for multiplexing both synchronous and asynchronous data with high efficiency.
Recently, statistical multiplexers for multiplexing both synchronous and asynchronous data channels have been developed. Such a multiplexer is disclosed in copending application Ser. No. 327,495, assigned to the assignee of this application, entitled Statistical Multiplexer with Dynamic Bandwidth Allocation for Synchronous and Asynchronous Channels and incorporated herein by reference. In that multiplexer, a central processor generates control frames for controlling the interleaving of asynchronous data frames and synchronous data channels to achieve high efficiency transmission. The processor monitors requests for transmission capacity for the various competing data sources in order to build appropriate control frames.
While the foregoing apparatus has proven highly effective in practice, a need has been recognized to more particularly adapt such apparatus to handle synchronous data in the so-called "Bisync" protocol. Such a protocol is described, for example, in the IBM Systems Reference Library publication "General Information--Binary Synchronous Communications," October 1970.